Filtration is used to separate one substance from another by entrapment within or on a filter medium. Air filtration, i.e., the removal of unwanted particles from air, can be important in both industrial and personal applications, especially as pollution in certain areas becomes worse. A variety of pulmonary diseases, induced by serious air pollution, can cause numerous health problems, including death, in numerous people, especially the elderly and children. Therefore, in recent years an increasing number of people have begun to wear face masks (e.g., in parts of China and Japan) due to air pollution or dust storms.
Air filters may be formed of various materials, including electro-spun nanofibers. Due to costs and the potentially extreme physical and chemical environments that some filters endure, any improvement in the durability, filtration efficiency, chemical resistance, weight and/or resilience from compression may be useful.